1. The invention of the telescope
One day in June 1608, Galileo heard that a Dutchman had put together a convex mirror and a concave mirror and made a toy. That night, Galileo sat down at the table and lit candles one after another. He thought again and again and wondered why two of these lenses together could have a magnifying effect. At dawn, Galileo decides to make one himself.
He found an empty tube, embedded a convex mirror on one end and a concave mirror on the other end, and made a small telescope. When you pick it up and look at it, you can enlarge the original object three times. Galileo wasn't satisfied, so he improved again and made another one.
He took the telescope and ran to the beach, only to see the vast sea with rolling waves and not a single boat. When he took the telescope and looked again, a ship was approaching the shorefrom afar. Practice has proven that it can amplify eight times.
Galileo continued to improve and create, and eventually his telescope was able to magnify the original object thirty-two times.
One night, moonlight filled the earth and Galileo took his telescope and pointed it at the moon. Hey, the moon isn't as smooth and flawless as people have said for thousands of years. It is like the earth, with mountains, deep valleys and volcanic fissures!
2. Free Fall Movement
People noticed the problem of falling bodies early on. Before Galileo, Aristotle's theory in ancient Greece believed that objects fell at different speeds. Its falling speed is proportional to its weight. The heavier the object, the faster it falls. For example, an object weighing ten kilograms falls ten times faster than an object weighing one kilogram.
For more than 1,700 years, in books and on school podiums,this doctrine which violates the laws of nature is taught like the Bible, and no one dares to doubt it. Indeed, Aristotle proposed the “Earth-Centered Theory,” which was consistent with the interests of the slave-owning class and the feudal ruling class. Therefore, Aristotle's other theories were also protected.
Galileo chose the Leaning Tower of Pisa as its test site. One day, he took two solid iron balls of the same size but different weights, a solid iron ball weighing one hundred pounds and a hollow iron ball weighing one pound, and climbed the leaning tower more than fifty meters high. Under the tower, there were many people coming to watch. Everyone talked a lot and some made fun of him: "This young man must be crazy, let him go wild! Can Aristotle's theory still be wrong?"
I saw Galileo appears at the top of the tower, Holding an iron ball in each hand, heshouted: "The people below can see clearly, the iron ball has fallen." He opened both hands at the same time. People saw that the two iron balls fell in parallel and landed on the ground almost at the same time. Those who made fun of him were stunned.
3. The Law of Universal Gravitation
Newton was alone in the orchard at home, while he was walking and thinking about a problem, he accidentally came across an apple tree in the orchard. . At that moment, an apple fell on his head. Newton suddenly woke up from the problem and picked up the apple. At that moment, he asked himself another question: why did the apple fall to the ground instead of floating in the sky? Ultimately, Newton proposed a universal law that produces the simplest phenomenon: universal gravitation.
One day, the nanny was going out. Before leaving, she told Newton: "I have something to do. I'm going out infirst. If I'm hungry, go boil some eggs. I've boiled some water." The nanny came back and found Newton taking a pocket watch. She went to cook. But Newton was working on inventions. This story tells us not to get too involved in one thing and to stop when it is time to stop
4 Watt's story
In the middle of the 18th century, there was a professor named Ridder at l. 'Glasgow University in England one night he invited Watt into his office and said to Watt: "I know you are a very clever machine repairman, and I want to ask you to do me a favor." /p>
Watt said: "How can I help you?"
Professor Reid said: "My set of machine plans has been stolen. But it is very difficult to build this machine according to the plans. The person who stole the plans will definitely come to you to help you with the treatment. If this person is coming for yous see, please tell me."
At this moment, a young assistant of the professor came in with a kettle and prepared a cup of coffee for each of them. . The Assistant put the kettle on the stove, closed the door and walked out. The teacher got up, walked to the door and locked it.
The teacher and Watt were drinking coffee and talking about the drawings. teacher. Gradually, Watt felt dizzy. He guessed that there was something wrong with the coffee. He only felt weak and fell asleep after a while. p>When Watt woke up, it was already the next day. When he opened his eyes, he saw that Professor Risted was dead. There was a five-centimeter-long needle with a cap on the professor's neck. Watt climbed up with support and went to open the door, only to find that the door was locked and the key was on the professor's body. Watt remembers what happened last night.denies it and suspects it was the assistant who did it.
But the assistant went out and never came back. Who put the needle in the professor's neck? He looked at the poisoned needle and the cap on the professor's neck for a long time, and finally understood: when water vapor expands, its pressure is nearly a thousand times that of water.
When the assistant put the kettle on the stove, he put a cork with a poisoned needle in the spout and pointed the spout at the teacher's neck. When the water was boiling, because the spout was blocked by the cork, the steam pressure continued to increase. Eventually, the steam pressure reached a certain level and the cork shot out with a poisoned needle, hitting the professor.
After police arrived, Watt shared his thoughts. After police investigation, it was discovered that the murderer was the professor's assistant. Later, Watt movedsteamed water and invented the steam engine.
5. Faraday's Story
Faraday was born on September 22, 1791 into a family of blacksmiths in Newington, Surrey. At the age of 13, he worked as an apprentice newspaper delivery boy and book binder in a bookstore. He has a strong thirst for knowledge and takes all his time off. He eagerly tried to read all the books and documents he had bound from the beginning.
After reading, I also copied the illustrations and took careful reading notes. I used a few simple utensils to conduct experiments according to the book, carefully observed and analyzed the experimental results, and transformed my attic into a small laboratory. . After staying in that bookstore for eight years, he forgot about food and sleep and studied voraciously. When he later recalled this period of his life, he said: "It was in my free time that II began to find my philosophy in these books.
Two of these books were useful to my personality. One is “Britain”, “Encyclopedia”, from which I learned about the concept of electricity; the other was Madame Massey's "Chemical Dialogues", which gave me the scientific basis for this course."
Faraday was mainly engaged in research on electricity, magnetism, magneto -optics and electrochemistry, and made a series of major discoveries in these fields After Oersted discovered the magnetic effect of electric current in 1820, Faraday proposed the bold idea of "generating electricity by. from magnetism" in 1821 and began arduous exploration
In September 1821, he discovered that a live wire could rotate around a magnet and that the magnet could rotate around a. current-carrying conductor For the first time, he achieved the conversion of an electromagnetic field into.an electromagnetic field. mechanical field, thus establishing a laboratory model of an electric motor.
After numerous experimental failures, the law of electromagnetic induction was finally discovered in 1831. This great historical discovery allowed humanity to master the methods of mutual conversion of electromagnetic energy, mechanical energy and electrical energy, and became the basis of modern technology of generators, motors and transformers.